1. Field of the Invention
The present invention relates to a color video printer, and more particularly to a device for maintaining the clearance between a Cycolor film of the U.S. MEAD IMAGING CO. and the head of a film exposing CRT constant in a color video printer during transfer the Cycolor film.
2. Background Art
As shown in FIG. 1, the conventional color video printer using the Cycolor film comprises a film roll 3 carrying a film 3', a feeding roll 2 for feeding the film, a film exposing CRT 1 for exposing to light the film 3' fed by the feeding roll 2, the feeding roll 2 being mounted in one side of the film exposing CRT 1, first and second idler rolls 4a and 4b for guiding the film 3', a capstan roll 10 and pressure rolls 6 provided between the first and second idler rolls 4a and 4b for driving the film, and first and second guides 8 and 9 for cooperating with the first and second idler rolls 4a and 4b to guide the film.
A plurality of guide holes are provided in the edges of the film 3' receiving a plurality of projections 2a formed on the periphery of the feeding roll 2, so that when the feeding roll 2 is rotated clockwise, the film 3' moves in the direction of the arrow indicated in phantom line in FIG. 1 wound around a winding roll 5. The feeding roll 2 and winding roll 5 are driven by different motors.
Thus being loaded, the film 3' is exposed to light according to the signals generated by the head 1a of the film exposing CRT 1, and then the exposed film is impressed onto a printing paper 7 by means of the pressure roll 6 transferring the image thereof to the paper. Finally the paper containing the image is discharged.
In this case, when the film 3' is exposed to the light rays emitted by the head 1a of the film exposing CRT 1, the toner laid on the film 3' is hardened in conformity with the intensity and wavelength of the light rays. Hence, the light rays emitted from the head 1a towards the film 3' should be made not so as to diffuse by maintaining the clearance between the head 1a and film 3' constant.
However, since the conventional color video printer has no such means for maintaining the clearance between the head 1a and film 3' constant, the film 3' is not properly exposed so as to result in an unclear printed image.